Adjusting device of warp tension in automatic looms



Aug. 28, 1934. NOGAMY 1,971,694;

ADJUSTING DEVICE OF WARP TENSION IN AUTOMATIC LOOKS Filed May 9, 1933 A \NVENT'OR.

Patented UNITED STATES ADJUSTING DEVICE 0F WARP TENSION 1N AUTOMATIC LOOMS Yaejy Nogamy, Nagoya, Japan Application May 9, 1933, Serial No. 670,130 In Japan December 14, 1932 1 Claim. (Cl. 139-410) ally been used to counteract-the rotation of a worm casing to be rotated by the tension of the warp, mounting the worm casing on a shaft connected to one end of the warp beam and a means to rotatethe shaft by worm and worm wheel op erated by the slay sword through a pawl and ratchet mechanism.

In prior devices, the pawl is operated through a simple lever by the slay sword, whereby the movement of the ratchet wheel can not be magnifled although the warp tension is slightly increased.

This invention has for its object to obviate this drawback and to obtain an effective adjusting device to be operated by a small variation of the warp tension. y

The essential feature of this invention consists of a compound lever mechanism provided between the let off means and the slay sword. This special device can magnify the rotating movement of the ratchet wheel in accordance with the small variation of. the warp tension. p

. One embodiment of the invention is illustrated in the accompanying drawing in which;

Fig. 1 is a front elevation-of the device.

Fig. 2 shows the sectional plan along the line A- B in Fig. 1.

the drawing, 1 designates a shaft connected to one end of the warp beam (not shown) to rotate together with the said warp beam. A worm wheel 2 is secured on the shaft 1 which rotatably carries a worm wheel casing 4. A worm 3 meshing with the worm wheel 2 is held on the sha 5 by the ends of the casing 4.

A pawl arm 7. and a fulcrum arm 8 are loosely mounted on the worm shaft 5 and a ratchet wheel 6 is keyed on said shaft between the two arms 'I and 8.

A counter lever 9 pivoted to the loom frame has a counter weight 10 adjustable on the lever which is connected to the worm wheel casing 4 by a chain 11 winding partly round the casing.

The rotating momentum of the casing 4 caused by the tension of the warp letting off the warp beam has-normally'been balanced by the counter weight 10 on *thelever 9.

When the warp tension increases the worm wheel casing 4 is rotated against the counter weight 10, thus the shaft 5 rocksaround the shaft 1 together with the pawl arm '7, the ratchet wheel 6 and the fulcrum arm 8.

A slot link .12 having a curved arm a and a straight arm b is pivoted by an upright leg 13 on the bearing 14.

A bell crank 15 consisting of the slotted arms 0 and d is provided with an upright leg 16 supported on the bearing 14.

The free ends of the pawl arm 7 and of the fulcrum arm 8 are inserted into the slot on the arm a of the link 12. 3

' The free end of the fulcrum arm 8 is also inserted into the slot on the arm c of the bell crank 15.

The arm at of the bell crank 15 is connected by a rod 1'! to the slay sword (not shown) which reip'rocates at a constant speed.

The operation of this device can be divided, for l the sake of convenience, into two systems of moticn. One is the rocking motion'of the shaft 5 7 about the shaft 1 in accordance with the variation of the warp tension and the other is the, lever motion of the compound lever which is operated by the slay sword.

In the rocking system, when the worm shaft 5 rocks about the shaft 1 by increase of the warp tension, the free ends of the arms 7 and 8 are caused to perform arc motions along the slots in the link 12 and inthe arm 0 of the bell crank about the shaft 1 as center.

In the lever motion, the compound lever mechanism consisting of the arm 0 of the bell crank,

the slot link 12 and the fulcrum arm 8 is caused to swing about the legs 16 and 13 respectively and simultaneously, with this swinging motion .the pawl arm 7 and the fulcrum arm 8 are caused to perform lateral arc motions about the worm shaft 5.

When the casing 4 rotates the direction shown by the arrow in'Fig. 1 by increasing of the warp tension, the shaft 5 is rocked about the shaft 1 and the arm 7 and 8 move to the positions 7' and 8' "illustrated by the chain lines in Fig. 1.

It is clear from the principle of a compound lever that the leverage of the link lever 12-is greatly increased when the fulcrum arm is displaced into the position 8. Moreover, as the arm a of the link lever 12 curves upwardly, the

amplitude of the lateral arc motion of the pawl arm 7 is increased by geometric progression when the pawl arm '7 is displaced to the position'l.

Thus the feed motion of the ratchet wheel 6 by means of the pawl arm 7 is greatly increased if the warp tension increases a little and the resuit is the sensitive and effective adjusting of the warp tension.

It must be understood that this adjusting device can be modified in its construction without any change in the spirit of the invention.

Having explained the nature of this invention in the specification and on the attached drawing, I now declare that what I claim is:.

An adjusting device for the warp tension in automatic looms, comprising a worm wheel secured on a rotatable shaft connected to one end of the warp beam,-a worm shaft provided with a worm meshing with the worm wheel, a worm wheel casing rotatably mounted on the said rotat- 1 able shaft, a ratchet wheel,'a pawl arm and a fulcrum arm arranged on the worm shaft, a slot link having a curved arm and a straight arm, and a slot bell crank under the worm shaft and in parallel therewith the free ends of the pawl an arm and fulcrum arm engaging the slots in the link and the bell crank in such a manner that YAEJY NOGAMY. 

